Profinet Communication - Epson RC90 Manual

1.6.3 PROFINET Communication

PROFINET is designed to support all applications in a plant versatilely with one bus.
Therefore, PROFINET has three different performance levels as described below.
For RC620 option fieldbus I/O, "2: RT (Real-time)" communication is supported.
1: NRT (Non Real-time)
This communication is based on TCP/IP.
This is used for applications where real-time communication is not required, such as
inter-unit communication and parameter communication.
2: RT (Real-time)
By adding a software protocol to the standard Ethernet hardware, this method
actualizes real-time communication with approximately 10 ms intervals.
In particular, by defining a priority in VLAN tag (IEEE803.1Q) in Ethernet frame, RT
frame is processed with a higher priority to non-real-time data (NRT, TCP/IP, etc.)
RT can offer almost the same performance as the existing fieldbus.
3: IRT (Isochronous Real-time)
Isochronous real-time communication (IRT) guarantees that communication is surely
executed within an arbitral communication time (Deterministic) at a higher level than
Real-time communication (RT).
This enables a clock rate of < 1 ms and a jitter precision of < 1 μs.
IRT is used for applications where a strict real-time performance is required, such as
motion control. As a communication hardware, switch-function-embedded special
ASIC is used. This method guarantees the real-time performance by dividing the
communication band on Ethernet.
RC700 / RC90 Option Fieldbus I/O Rev.14
1. Introduction
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